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CodeSignal sudoku2 Solution
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function sudoku2(grid) { | |
return ( | |
validateRows(grid) && | |
validateRows(rotateGrid(grid)) && | |
validateSubGrids(grid) | |
); | |
} | |
// Validate each row. | |
function validateRows(grid) { | |
let valid = true; | |
for (const row of grid) { | |
if (!valid) { | |
break; | |
} | |
let dict = {}; | |
row.filter(item => item !== ".").forEach(item => { | |
if (dict[item]) { | |
valid = false; | |
} else { | |
dict[item] = 1; | |
} | |
}); | |
} | |
return valid; | |
} | |
// Rotate the grid by 90deg. | |
// This allows us to then validate the columns as rows. | |
function rotateGrid(grid) { | |
return grid.map((inArr, i) => { | |
const newArr = []; | |
for (const arr of grid) { | |
newArr.push(arr[i]); | |
} | |
return newArr.reverse(); | |
}); | |
} | |
// Convert each 3x3 grid into a row of 9. | |
// This allows us to validate the sub grids as rows. | |
function validateSubGrids(grid) { | |
const subGrids = []; | |
const getSubGridRow = function(grid, curRow, curCol) { | |
const currentSubGrid = []; | |
for (let row = curRow; row < curRow + 3; row++) { | |
for (let col = curCol; col < curCol + 3; col++) { | |
currentSubGrid.push(grid[row][col]); | |
} | |
} | |
return currentSubGrid; | |
}; | |
for (let i = 0; i < grid.length; i += 3) { | |
for (let j = 0; j < grid.length; j += 3) { | |
subGrids.push(getSubGridRow(grid, i, j)); | |
} | |
} | |
return validateRows(subGrids); | |
} |
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